1. State Key Laboratory of Rare Earth Resource Utilization; Changchun Institute of Applied Chemistry; Chinese Academy of Sciences; 5625 Renmin Street Changchun Jilin 130022 P. R. China
2. University of Chinese Academy of Sciences; Beijing 100049 P. R. China
3. College of Chemistry and Chemical Engineering; Inner Mongolia University for the Nationalities; Tongliao 028000 P. R. China